src/test/compile-fail/hrtb-conflate-regions.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Test that an impl with only one bound region `'a` cannot be used to
  12 // satisfy a constraint where there are two bound regions.
  13
  14 trait Foo<X> {
  15     fn foo(&self, x: X) { }
  16 }
  17
  18 fn want_foo2<T>()
  19     where T : for<'a,'b> Foo<(&'a isize, &'b isize)>
  20 {
  21 }
  22
  23 fn want_foo1<T>()
  24     where T : for<'z> Foo<(&'z isize, &'z isize)>
  25 {
  26 }
  27
  28 ///////////////////////////////////////////////////////////////////////////
  29 // Expressed as a where clause
  30
  31 struct SomeStruct;
  32
  33 impl<'a> Foo<(&'a isize, &'a isize)> for SomeStruct
  34 {
  35 }
  36
  37 fn a() { want_foo1::<SomeStruct>(); } // OK -- foo wants just one region
  38 fn b() { want_foo2::<SomeStruct>(); } //~ ERROR E0277
  39
  40 fn main() { }